NO165176B - SET FOR USE IN TREATMENT OF PATIENT DISORDERS. - Google Patents

Abstract

An instrument (27) for use in inserting a surgical implant into a cavity in a patient's bone characterized in that said instrument (27) comprises:an elongated rod (21) having a first end and a second end, said rod (21) having an externally threaded portion (23) adjacent said first end and an externally smooth portion (29) extending from said externally threaded portion (23) towards said second end, and said rod (21) being axially cannulated over at least a portion of its length so as to be capable of fitting over a surgical guide wire;a hollow sleeve (31) receiving said elongated rod (21), said sleeve (31) being capable of sliding movement upon said externally smooth portion (29) of the rod (21); andmeans (35) for advancing the hollow sleeve (31) along the externally smooth portion (29) of the rod (21) towards said externally threaded portion (23),said advancing means (35) positively preventing movement of the sleeve (31) along the rod (21) in a direction away from said externally threaded portion (23) while it is engaged with the sleeve (31), whereby advancement of the sleeve (31) can be stopped without relaxing the force being placed upon it by said advancing means (35).

Description

The present invention relates to a set for use in the treatment of femur disorders of various types caused by injury, disease or congenital defect, which comprises the following components: an elongated epiphyseal/metaphyseal implant, with an anterior end part and a posterior end part, for retaining the bone by the front end part,

a medullary inner rod having a distal end and a proximal end,

a bent side plate consisting of an elongated plate portion, for attachment to the outer crotal wall of the femoral shaft, and an integral, hollow sleeve extending at an angle from one end of the plate portion to extend into the femur, when the plate portion is attached to the cortical wall, and

means for joining the epiphyseal/metaphyseal implant

and the medullary inner rod at one of the ends of the rod so that the epiphyseal/metaphyseal implant forms an angle with the medullary inner rod.

Internal fixation of femur fractures is one of the most common orthopedic operations. Many different types of femur fractures occur in practice, such as femoral neck fractures and fractures in the intertrochanter, midshaft and distal condyle zones. The femur can sometimes break cleanly into two large fragments along its length

a well-defined fracture line, and in other cases in many smaller fragments. Often, more than one type of fracture can occur simultaneously in different femur zones in an injured patient.

Over the years, many different implants have been produced for use in the internal fixation of femur fractures. Although many excellent devices have been produced, several general problem areas remain. Firstly, almost all of the currently available implants are intended for very special use which is limited exclusively to special, anatomical zones of the femur. A hospital must therefore, at great expense, maintain a very large and varied stock of various implants, in order to be able to meet all possible situations. These implants are usually not compatible, which means that they cannot be joined in case of complicated fracture patterns that extend into different anatomical zones of the femur. Secondly, each implant has its own unique characteristics and shortcomings, and the use of several of the known implants requires the use of an operating technique that is unique to this implant, and in some cases complicated and difficult. Consequently, the possibilities for an unfortunate choice of ^implant and for errors on the part of the surgeon during implantation will inevitably increase. Finally, reactions between tissue and stainless steel implants and certain other surgical implant alloys can reduce the effective life of the implant and necessitate premature removal from the patient's body.

A very commonly used device for internal femoral fixation consists of an elongated implant (nail, screw, pin, etc.) which is placed along the longitudinal axis of the femoral neck with its front end anchored in the joint head of the femur, for stabilization of a femoral neck fracture. The elongated implant can be implanted alone or combined with another implant, such as a side plate or a medullary rod. The front part of the implant is typically arranged for secure retention of the femoral joint head (external threads, expanding arms, etc.), but the insertion of such gripping parts can cause many significant difficulties. Firstly, implants with sharp edges, for example external threads, will tend to migrate towards the bearing surface of the hip joint after implantation. Such rapid walking or cutting off the femoral head can cause extensive damage to the adjacent hip joint. The externally threaded implants can also cause large stress concentrations in the adjacent bone during implantation, which can result in overstretching of the threads formed in the bone, whereby the gripping connection is obviously weakened.

The movable arms of known expansion arm devices are usually free at one end and fixed at the other end to the main part of the front part of the implant. For that reason, all fatigue loads will be concentrated at the fixed ends of the arms so that bending moments of an undesirable magnitude occur at the attachment points.

The general types of surgical implants used for internal femoral fixation include angled side plates, intramedullary rods (see, e.g., European Patent Application 186,656A1 and US Patent No. 4,453,539), bone screws (see, e.g., West German Offenlegungsschrift 2,747,312 ) and epiphyseal/metaphyseal implants (see e.g. US patent no. 3,892,232). It is known to make such implants from an elastic titanium-based alloy (see US patent no. 4,040,129). Angled side plates include an elongated bone plate portion and a hollow sleeve or fixed limb that is designed to extend into the thigh and may be designed to accommodate or fit into the tail portion of an epiphyseal/metaphyseal implant (see, e.g., US Patent No. .3,459,180; US Patent No. 3,782,374; US Patent No. 3,805,775;

US Patent No. 4,379,451 and US Patent No. 4,494,535). Integral side plates/leg rivet devices are also known (see eg European Patent Application 147.265A1 and West German Offenlegungsschrift 1.541.151). Devices of an intramedullary rod with an epiphyseal/metaphyseal implant are also known (see, e.g., US Patent No. 3,433,220). However, the possibility of extensive modular connection of the various types of surgical implants included in an internal femoral fixation had generally not been achieved to date.

As previously mentioned, elongated implants used for stabilization of femoral neck fractures are often connected to a side plate which is in turn fixed, e.g. with bone screws, to the outer cortical wall of the adjacent femoral shaft. This mounting type is often chosen when a femoral neck fracture forms part of a more complicated fracture pattern including one or more fractures in the femur's metaphyseal and/or diaphyseal zone. The surgeon naturally wants to be able to choose the appropriate length for the side plate, depending on the particular, traumatic condition of the patient's femur. The surgeon's flexibility in this respect, however, is usually dependent on the hospital having an expensive supply of implants at its disposal.

It is an aim of the present invention to produce a modular system of femoral inner implants with associated instrumentation which is suitable for the treatment of several different fracture patterns and other functional disorders, and which has a minimal number of joinable system components with consequent simple and uncomplicated surgical processes with less extensive , surgical interventions and shorter operating times.

The above and other aims of the invention have been achieved by the set's components being dimensioned in such a way that the elongated epiphyseal/metaphyseal implant can be connected to the bent side plate by inserting the posterior end part of the implant into the hollow sleeve, and where the elongated epiphyseal/metaphyseal implant also can be connected to the marrow hole inner rod by using said connecting means.

The implant can thus be joined either with the medullary inner rod, for example to create a Y-nail-type assembly for the treatment of an unstable subtrochanteric fracture pattern, or with the bent side plate, for example to create a side plate-pin assembly for the treatment of another fracture pattern . The medullary inner rod can either be connected to the elongated epiphyseal/metaphyseal implant, or implanted independently of said implant and of the bent side plate.

The new equipment can be used both for the treatment of various trauma conditions and for the repair of femur injuries of other types, such as congenital, unfused deformities and pathological deformities (e.g. Pagef's disease), and is also suitable for use in the prophylactic fixation of a weakened leg , bone defects, etc. and for carrying out osteotomy treatments. Simple and uncomplicated surgical techniques can be used, and operating time and implantation interventions can be kept to a low level.

The term "elongated epiphyseal/metaphyseal implant" is used in the description for an elongated implant which is to be used in such a way that, after implantation, it extends from the immediate epiphyseal zone of the femur into the adjacent metaphyseal zone, or from the medial epiphyseal zone of the far femur . In general, the elongated epiphyseal/metaphyseal implant can consist of a pin, rivet, screw or the like. The hollow inner rod is preferably equipped with axially extending grooves and provided with at least one continuous channel, for the reception of a locking screw, at the far end.

The femoral module implant system may advantageously include components in addition to the important epiphyseal/metaphyseal implant, the medullary inner rod, the bent side plate and connecting means for joining the epiphyseal/metaphyseal implant and the medullary inner rod. Thus, the equipment preferably includes an elongated bone plate for attachment to the outer cortical wall of the femoral shaft. The elongated leg plate and the bent side plate are dimensioned in such a way that the elongated leg plate can be connected to the bent side plate's plate part and thereby form an extension of the plate part's effective length, without this requiring the insertion of two complete, bent side plates. Of course, the elongated leg plate can, if desired, be used by itself in a conventional way. Preferably, several elongated leg plates of different lengths are included in the equipment.

In another, preferred version according to the invention, the equipment comprises a far support plate with a relatively flat and elongated, sharp part for attachment to the lateral and far femur shaft, and a relatively arched, far part for attachment to the lateral, far femur condyle. In this embodiment, the equipment comprises at least one elongated leg plate which can be joined both with the bent side plate's plate part and with the fast part of the far support plate to extend the effective length, if desired.

The new equipment according to the invention preferably includes a number of threaded and self-threading cortical bone screws for use in securing the elongated plate portion of one or more bent side plates to the outer cortical wall of the femoral shaft and, if the equipment includes a medullary inner rod with an outer, through channel and a or several elongated bone plates, attaching the far end of the medullary inner rod to the far foreleg part, attaching the bone plate(s) to the outer cortical wall of the femoral shaft and joining the plate part(s) and the bone plate(s) in mutual axial alignment. The equipment preferably includes a larger number of such screws, each with a head and a threaded shaft, which are identical except for variations in the length of the threaded shafts. Although not each of these screws can be used in all of the above cases (short cortical screws cannot, for example, be used when fixing the far end of the medullary inner rod), the use of a number of threaded and self-tapping cortical bone screws of uniform screw head and screw shank shape, (apart from variations in screw shank length) provide significant opportunities for replacement during use and reduced intervention scopes, and the surgeon only needs to be familiar with a single group of cortical scrubber characteristics, properties and methods of use. Furthermore, the bone screws can be used independently as bone anchoring screws, for holding bone fragments together during the healing of a fracture. It is preferred that the heads of the cortical screws and the openings in the plate part(s) and the leg plate(s) for receiving the screws are designed in such a way that the screws can perform a uniform rotation,

in relation to the plate part or leg plate, within a cone with an apex angle of at least 20°, when the screw head is fully inserted into the corresponding opening. The underside of the universal screw head can, for example, be spherically rounded (convex towards the bone) and the contact surfaces of the screw receiver openings correspondingly rounded (concave from the bone).

The components of the new equipment according to the invention are preferably made of an elastic, physiologically neutral titanium base alloy, such as Ti-11.5Mo-6Zr-4.5Sn, Ti-6A1-4V or Ti-3A1-2.5V. The physiological inactivity of such alloys reduces the possibility of adverse tissue reactions (equal to, for example, stainless steel) and will contribute to increasing the product's lifetime in the living organism after implantation. Most of the currently available implants for internal fixation or repair of femur fractures or other injuries are made of very rigid materials, which in many cases results in excessive "load shielding", whereby too much of the loads transferred to the femur are absorbed by the implant and not of the healing bone in the fracture zone. Load shielding can delay the healing of the fracture and weaken the surrounding bone tissue. The problem of load shielding will be largely remedied by the equipment's components being manufactured from an elastic titanium base alloy.

According to a preferred distribution of components, the equipment comprises: 1) two epiphyseal/metaphyseal implants of different lengths, 2) a bent side plate where the hollow sleeve and the plate portion form an oblique angle with each other, so that the hollow sleeve can extend into it intertrochanteric zone when the plate part is attached to the outer cortical wall of the adjacent femoral shaft. 3) a bent side plate where the hollow sleeve and the plate portion form a largely right angle, so that the hollow sleeve can extend into the far condylar zone of the femur when the plate portion is attached to the outer cortical wall of the far femoral shaft, 4) a medullary inner rod (preferably with a through channel at the distal end), 5) means for joining the shorter of the two epiphyseal/metaphyseal implants with the medullary inner rod at the sharp end of the rod, to create a Y-nail type assembly, 6) a number of sponges - and cortical-bone screws, and 7) at least one elongate bone plate that can be connected in axial alignment with each of the bent side plates plate portion, to increase the effective length. The shortest epiphyseal/metaphyseal implant can also be joined with the mostly right-angled side plate, while the longest epiphyseal/metaphyseal implant can be joined with the obliquely angled side plate. With this highly preferred component distribution, the equipment's components can be joined in different ways or used separately for the treatment or healing of most types of femur fractures and other femur injuries that are commonly encountered in orthopedics.

In addition to the overall modular principle for the femur implant system, the invention also deals with the special design of various system components. The scope of the invention thus includes a new bone implant for use in stabilizing a bone fracture, and comprising an integrating, largely cylindrical expansion sleeve with a smoothly rounded, peripherally closed dome at one end, a peripherally closed, circular ring at the other end where a number intermediate, thin and elongated strip parts are attached to the peripherally closed vault and ring and having varying radial thickness in the longitudinal direction and profiled outer surfaces,

and an elongated pressure piston with a largely cylindrical base portion of practically the same diameter as the inner diameter of the expansion sleeve's peripherally closed, circular ring, at one end. When the expansion sleeve is inserted into a cavity in a

bone fragment on one side of a fracture, the pressure piston must be advanced through the circular ring and into the sleeve, with the largely cylindrical base portion at the front, the row of thin and elongated strip parts in the sleeve will be caused to expand radially outwards, whereby bone fragments are securely held.

The new bone implant according to this feature of the invention may, but not necessarily, consist of an epiphyseal/metaphyseal implant.

The descriptive term "peripherally closed" is used to denote that a path can be followed completely around the periphery of the hollow structure with an axis without breaks or gaps or other interruptions in the massive material of the structure. A split ring will thus not be peripherally closed, unlike a full ring. The unbroken path may have an irregular contour shape but must run continuously through a full 360° in relation to the axis of the construction in question.

As the expansion sleeve for the bone implant, according to this feature of the invention, has an evenly rounded, peripherally closed vault at the front end, the likelihood of a significant, rapid implant migration or "cut-out" in the femoral head is significantly reduced (cf. for example with an externally threaded bone screw or a three-flange rivet) . This is a very important feature that will lead to a considerably increased product life and a significantly reduced bone damage. It is also of great importance that the expandable strip parts of the expansion sleeve extend between and are connected at their opposite ends by two peripherally closed structures (ie the smoothly rounded dome at the front end of the expansion sleeve and the circular ring at the rear end), as this imply that these thin strip parts have no free ends which may contribute to excision or become stuck to the side wall of a prepared cavity in the patient's bone structure during implantation.

It is not necessary for a significant tearing moment to be transmitted during implantation (which could cause rotation of the femoral head during insertion or detachment of bone material), and the radial expansion of the profiled strip parts provides a very effective and safe bone gripping effect that is distributed along the outer surface of the sleeve without cause excessive stress concentrations in the bone at the implant. As the expandable strip parts are anchored in both parts, fatigue stress will not be concentrated at one end of the strip parts either, and the bending moments will be more evenly distributed along the strip part. This new expansion sleeve implant has an operating mechanism that is simple and foolproof and without complicated, moving parts that could fail during implantation. The pressure piston is preferably provided with a raised, annular rib which is arranged at the rear end of the base portion and which can be fitted into a corresponding groove in the inner wall of the expansion sleeve's circular ring, when the pressure piston is completely inserted into the sleeve. With the help of this rib and groove combination, the pressure piston and sleeve can be locked against unwanted mutual axial displacement after implantation.

It is highly preferred that the expansion sleeve is made of an elastic material, e.g. a titanium-base alloy. The elastic strip parts of the expansion sleeve will in this case expand radially outwards by elastic deformation, when the pressure piston is advanced in the sleeve, and will regain its original shape (to, if desired, facilitate the removal of the sleeve) when the piston is withdrawn. It is also desirable, whether the sleeve is made of elastic material or not, that it is designed in such a way that openings are formed when the sleeve is in a rest position. To promote fixation of the bone implant, an extrudable material, such as bone cement, can be filled into the sleeve and then extruded through the openings therein to the bone-implant interface while advancing the plunger. The desired openings in the sleeve can consist of separate slits which are formed between the strip parts when the sleeve is in a rest position, or of openings of another type.

According to a preferred surgical implantation technique, a guide wire is placed at the desired location in the patient's leg, a tubular and generally cylindrical cavity for receiving the implant is created with a drill or a reamer, the expansion sleeve is fixed (preferably releasably) by its smooth rounded dome into an elongated , tubular rod (connected to the pressure piston) which extends into the expansion sleeve and through its peripherally closed, circular ring, the expansion sleeve is inserted and held in position in the prepared cavity in the bone by means of the elongated rod (which is inserted over the guide wire), and the pressure piston is advanced along the insert rod to the interior of the expansion sleeve. The insert rod is preferably provided with external threads at one end, while the expansion sleeve includes a threaded and continuous, axial central channel which can be releasably connected to the externally threaded end of the insert rod.

Furthermore, the invention comprises a preferred instrument for use during the introduction of a surgical implant (for example the above-mentioned, new expansion sleeve-provided bone implant according to the invention) in a cavity in a patient's bone. This new introducer consists of an elongated, axially knurled rod having an externally threaded portion at one end thereof and an externally smooth portion extending from the externally threaded portion toward the other end of the rod, a hollow sleeve that receives the elongated rod and which can be moved slidingly on the smooth outer side of the rod, and means for advancing the hollow sleeve along the smooth outer side of the elongated rod and towards the externally threaded part of the rod. The sleeve's advancement device is preferably profiled in such a way that it will safely prevent movement of the hollow sleeve along the rod in the direction from its externally threaded part, when the rod is connected to the sleeve. Suitable sleeve advancing means include a knurled knob screwed onto a second externally threaded portion of the elongate rod, on the opposite side of the smooth outer portion relative to the aforesaid first externally threaded portion, or a spreader tool for engagement with locking teeth which is arranged on the elongated rod on the opposite side of its smooth outer part.

By using the implantation technique and insertion instrument that is preferred and described above, with the instrument's hollow sleeve placed at the back while the implant's pressure piston is forced into the expansion sleeve, the new expansion sleeve and pressure piston-equipped bone implant according to the invention can be easily inserted into the prepared cavity in the patient's bone in a simple, surgical process that is not time-consuming and entails a minimal risk of surgical error or equipment failure and which gives highly repeatable results time after time. The same insertion instrument can be used for bone implants of different lengths. It is an important feature that the sleeve's advancement device will reliably prevent backward movement of the sleeve along the rod, as it will thereby be possible for the surgeon to interrupt the forward movement of the pressure piston during insertion into the expansion sleeve without thereby having to relieve the compression force exerted against the piston by the hollow sleeve on the insertion instrument.

The invention is further characterized by a new, elongated leg plate with an upper side that should face away from the patient's leg and which is wider than the lower side that should face the patient's leg, and two side surfaces that connect the upper side with the lower side and that slope inwards towards each other in the direction from the upper side towards the underside. The bone plate has a largely constant thickness between the two side surfaces and can be attached to a patient's bone by means of bone locking parts that are received in openings in the bone plate. As the lower side closest to the bone is narrower than the upper side (the width is preferably 70 - 90% of the upper side width), where the stresses from the physiological bending moments that are transferred to the plate will be greatest, the necessary periosteal tissue removal, which is carried out closest to the bone, can be until the implantation is reduced without this being excessively detrimental to the bone plate's bending strength. In a preferred embodiment, the upper side and the lower side are in transverse bone plate section, delimited by two concentric circular arcs, while the two side surfaces are delimited by two straight radial lines through the common center of the concentric circular arcs.

It is further preferred that an elongated leg plate according to this feature of the invention comprises two parallel and integrating, downward-directed rails which are placed on opposite sides of the underside and run largely along the full length of the leg plate.

Using these two rails will the underside of the leg plate

lifted away from the outside of the patient's bone and thereby favoring the vascularization of the bone directly below the underside, and preventing excessive weakening of this bone tissue.

As previously mentioned in connection with the modular femur implantation equipment or system according to the invention, it is very advantageous to use an elongated bone plate which can easily be joined to the elongated plate part of another, surgical implant by a simple, foolproof and time-saving operating method and thereby in effect increase the length of the elongated plate portion. The second surgical implant can, for example, consist of another bone plate, a bent side plate, an outer support plate or the like. It is therefore a further advantage of the new elongated bone plate according to the invention that it can be easily joined to a surgical implant with an elongated plate portion which is adapted to be attached to a patient's bone by means of bone anchoring parts which are received in openings in the elongated plate portion , and which includes an upper side and a lower side with a cavity arranged in the lower side at a free end of the plate portion and extending in the longitudinal direction from the free end to a shoulder portion forming an end of this cavity having a cross-sectional shape corresponding to to the cross-sectional shape of the elongated bone plate according to the invention. An important consequence of the mutually corresponding cross-sectional shapes, including the downward-sloping side walls, of the surgical implant cavity and the elongated bone plate is that the bone plate is "dovetailed" with the surgical implant, and thereby can only be introduced and removed from the cavity in the implant by relative axial movement through the cavity opening at the free end of the elongated plate portion of the implant. Nor can mutual turning movements of the surgical implant and the bone plate occur. When the end of the bone plate rests against the shoulder part at the other end of the cavity, any mutual translational movement of the surgical implant and the bone plate is excluded, apart from separation in the axial direction. By ensuring that at least one opening, for receiving a bone anchoring part, in the elongated plate part of the implant is flush with a corresponding and underlying opening in the bone plate, when the plate is inserted into the cavity of the implant and rests against the shoulder part at the end of the cavity, a stable and secure assembly of the surgical implant and the bone plate can be produced, where the length of the elongated plate portion of the implant is effectively increased by the elongated bone plate, when the implant and the joined bone plate are fixed together to the patient's bone.

Furthermore, the invention comprises a new far support plate for attachment to the outer cortical wall of the lateral far femur by means of bone anchoring parts which are accommodated in openings in the plate. The plate includes a relatively flat elongated hit portion for attachment to the lateral far femoral shaft and a relatively chromed far portion that curves out of the plane of the hit portion for attachment to the lateral far femur condyle.

In case of injuries, including a sagittal fracture through the far epiphyseal bone, a far support plate can be used with great advantage in connection with at least two French screws that are used for fracture reduction in the far condyle zone and which are placed close to, but without penetrating, the far part of the support plate. According to this feature of the invention, two spaces are left for the placement of a pair of French screws at the sides of a narrow neck portion which merges into a wider, generally rounded head at the far end of the far portion and an even wider far portion with a larger maximum width than the elongated, sharp part of the support plate. There is preferably arranged at least one long hole for receiving two leg anchoring parts in the head of the far part and two such long holes, one on each side, in the said far part. It is also preferred that the relatively flat, sharp part of the support plate is equipped with an appropriately sized cavity for a "dove-tail connection" with the new leg plate according to the invention in the same way and for the same purpose as described above.

Another distinctive feature of the invention concerns a new bone implant assembly which is intended for stabilizing a

fractured femur and comprising an elongate transverse piece with an anterior portion that can be received in a cavity in the femoral head and retain this, and a posterior portion that extends from the anterior portion into the intertrochanteric zone of the patient's femur and is equipped with a cylindrical, through channel which runs at an oblique angle in relation to the longitudinal axis of the cross-section and can thereby be brought approximately flush with the femur's internal medullary canal when the front part of the cross-piece is introduced into the femoral head,

a marrow hole inner rod with a distal end portion and a fast end portion, wherein the maximum diameter of the fast end portion is slightly smaller than the diameter of the cylindrical, through channel in the rear portion of the elongate crosspiece, so that the fast end portion can be received slidably and closely fitted therein through channel thereby permitting adjustment by rotation and displacement of the cross-piece relative to the core-hole inner rod, and separate, secure and active means for releasably interlocking the elongate cross-piece and the core-hole inner rod, to prevent mutual translational and rotational movement of the co-joined parts . The elongated cross-piece may consist of a single and complete part or of two or more disjointed pieces which are joined together before use. The cross piece can for example consist of a first part, for retaining the femoral head, and a second, separate part which can be releasably locked to the marrow hole inner rod and occupy the first part during use in an unlocked sliding fit. The phrase "separate, secure and active means for releasably interlocking the elongate cross-piece and the core-hole inner rod" is used as a designation for one or more structural elements which are separated from the outer sides of the elongated core-hole inner rod and the through channel in the cross-piece and which, by to be activated after the marrow hole inner rod and the cross piece have been previously joined, will effect a secure and releasable interlocking of the marrow hole inner rod and the cross piece. The presence of such a releasable locking part, for example a locking screw which is inserted into an internally threaded opening in the cross piece, to turn and thereby force a locking jaw firmly against the fast end portion of the marrow hole inner rod, will make it much easier to achieve the exact, desired interposition of the medullary inner rod and the elongated crosspiece in a special clinical case.

The elongated medullary inner rod preferably has a peripherally closed cross-sectional shape and is provided around the outer side with a number of longitudinal riffles which will prevent axial rotational movement of the implanted rod relative to the patient's femur and provide improved vascularization of the bone tissue adjacent to the rod outer side, and the releasable locking means comprise a locking screw and a locking tray which is fitted into an opening in the cross-piece. The locking shoe has an outer surface which corresponds to the axially knurled outer surface of the marrow hole inner rod, and which is forced against the outer surface of the marrow hole inner rod when the locking screw is screwed forward in the opening. In a more preferred form, the longitudinal cross-piece and the marrow hole inner rod are made of an elastic titanium base alloy. Most preferably, the core hole inner rod is produced as an extruded hollow part of Ti-3A1-2.5V alloy.

Furthermore, according to the invention, a new cancellous bone or cortical bone screw has been produced, consisting of elastic titanium base alloy, with a head and a partially or fully threaded shaft, with an axially extending groove of mostly star-shaped cross-section (e.g. a Torx (trade mark ) drive or Pozidriv (trademark) slot) with practically parallel and axially running walls, which are arranged in the screw head for receiving an instrument for driving the screw. Due to the design of the driver instrument-receiving groove in the new screw, the screw is much less susceptible to wear than, for example, a slotted screw, and this facilitates the introduction of the screw into a patient's bone and makes it practically possible to use eh elastic titanium base alloy as material for manufacture of the screw.

Other features of the invention will be apparent from a complete reading of the subsequent description and claims.

Without limiting effect, the invention is described in more detail below with reference to the accompanying drawings, in which: Fig. 1 shows an extended side view of an epiphyseal/metaphyseal implant according to the invention, with an expansion sleeve and an elongated pressure piston. Fig. 2 shows an axial section of the expansion sleeve at the implant according to fig. 1, in rest position. Fig. 2A shows an end view of the expansion sleeve according to fig. 1, in rest position.

Fig. 3-5 shows a longitudinal section along the pressure piston and

the common longitudinal axis of the sleeve, of the implant according to fig. 1 which illustrates three stages during the insertion of the pressure piston into the sleeve which is retained in a patient's bone. Fig. 6 shows an upper plan view of a high-speed, bent side plate which forms part of a modular implant system or equipment according to the invention.

Fig. 7 shows a section along the line 7-7 in fig. 6.

Fig. 8 shows a section along the line 8-8 in fig. 6.

Fig. 9 shows an upper plan view of an elongated leg plate

which is part of a modular implant system according to the invention.

Fig. 10 shows a section along the line 10-10 in fig. 9.

Fig. 11A and 11B show side views of a pair of cortical bone screws of different shaft lengths, which form part of a modular implant system according to the invention. Fig. 12A and 12B show side views of a pair of cancellous bone screws of different shaft lengths, which form part of a modular implant system according to the invention. Fig. 13 shows an enlarged, upper plan view of each of the cortical bone screws according to fig. 11A and 11B. Fig. 14 shows a section along the line 14-14 in fig. 9 showing the permissible side-to-side angulation of one of the cortical bone screws in FIG. 11A within one of the bone screw receiving instruments provided in the bone plate in fig. 9. Fig. 15 shows a vertical side view of the epiphyseal/metaphyseal implant according to fig. 1, the high-speed bent side plate according to fig. 6, the elongated leg plate according to fig. 9 and a number of cortical bone screws of the type shown in fig. 11A and 11B, all of which are joined and secured to a patient's bone shown in section.

Fig. 16 shows a section along line 16-16 in fig. 15.

Fig. 17 shows a section along line 17-17 in fig. 15.

Fig. 18 shows a side view of a surgical implant insertion instrument according to the invention, joined with the expansion sleeve and the elongated pressure piston at the implant according to fig. 1

Fig. 18A shows a section along the line 18A-18A in fig. 18.

Fig. 19 shows a side view of a medullary inner rod with an anterior-posterior arch, which forms part of a modular implant system according to the invention. Fig. 20 shows another side view, perpendicular to the view in fig. 19, of the marrow hole inner rod according to fig. 19.

Fig. 21 shows a section along the line 21-21 in fig. 19.

Fig. 22 shows a side view, partly in section of a fast end zone of a marrow hole inner rod of the type shown in fig. 19, illustrating the optional use of a removable hollow sleeve attached to the quick end portion of the marrow hole inner rod. Fig. 23 shows an extended, upper plan view of a connecting piece, a locking screw and a locking tray for an elongated medullary inner rod epiphyseal/metaphyseal implant which forms part of a modular implant system according to the invention. Fig. 24 shows a front end view, partly in section, of the items according to fig. 23. Fig. 25 shows a side view of an epiphyseal/metaphyseal implant of the type shown in fig. 1, but of shorter length, the marrow hole inner rod according to fig. 19 and the connecting piece, the locking screw and the locking tray according to fig. 23, all of which are joined and secured to a patient's bone shown in section, where the epiphyseal/metaphyseal implant and connecting piece together form an elongate cross-piece. Fig. 26 shows a lower plan view of a far, bent side plate which forms part of a modular implant system according to the invention.

Fig. 27 shows a section along the line 27-27 in fig. 26.

Fig. 28 shows a side view of an epiphyseal/metaphyseal implant of the type shown in fig. 1, but of shorter length, the far, bent side plate according to fig. 26, the elongated leg plate according to fig. 9 and a number of cortical bone screws of the type shown in fig. 11A and 11B, all of which are joined and secured to a patient's femur shown in section. Fig. 29 shows an upper plan view of an outer support plate which forms part of a modular implant system according to the invention. Fig. 30 shows a side view of the far support plate according to fig. 29. Fig. 31 shows a side view of the far support plate according to fig. 29, the elongated leg plate according to fig. 9 and a number of cortical and cancellous bone screws of the type shown in fig. 11A, 11B, 12A and 12B, all of which are joined and secured to a patient's far femur shown in section. Figs. 32A and 32B show side views of a pair of cortical bone screws of different shaft lengths, which are suitable for use as distal locking screws.

Where nothing else is stated, all implants are in accordance

1 - 32B showing various preferred embodiments of the invention, made from an elastic, physiologically neutral titanium base alloy.

An elongated epiphyseal/metaphyseal implant 1 according to the invention is shown in fig. 1. The implant 1 comprises an integrating, largely cylindrical expansion sleeve 3 and an elongated pressure piston 5. The sleeve 3 includes a uniformly rounded, peripherally closed dome 7 at one end, a peripherally closed, circular ring 9 at the opposite end and a number ( 8 in the shown version according to Figs. 1-5) identical practically rectilinear, elongated, thin and elastic strip parts 11 which extend between, and are connected at their opposite ends by and through the vault 7 and the ring 9. In the vault 7 there is provided with a central, threaded through axial channel 15, for releasable attachment of a slender insertion forceps to the vault. The strip parts 11 have profiled outer surfaces which will enhance the bone-gripping effect of the implant and which together form the cylindrical side wall of the sleeve 3, which, when the sleeve is in its rest position, has practically the same outer diameter as the outer diameter of the ring 9. As can be seen from fig. 2, each of the strip parts 11 has a thickness that varies along the strip part, so that when the sleeve is in its rest position, the sleeve wall has an inner diameter in a zone r^ at the ring 9, which is equal to the inner diameter of the ring 9, and an inner diameter in a zone r2 at a distance from the ring 9, which is smaller than the inner diameter of the ring 9. The strip parts 11 are not in contact with each other in the longitudinal direction, when the sleeve is in the rest position, but are instead separated by longitudinal openings 13 in the same number.

There is arranged at one end of the pressure piston 5 a largely cylindrical head part 17 of largely the same diameter as the inner diameter of the ring 9 on the sleeve 3, and a cylindrical stem part 19, of a smaller diameter than the head part 17, which extends between the head part 17 and the other end of the pressure piston. The pressure piston 5 is provided with longitudinal rifles, as shown in fig. 1. A rear end of the stem portion 19 includes an internally threaded recess 20 which can be connected with an externally threaded tool, if the pressure piston 5 is to be removed from the patient's bone after implantation.

A raised, ring-shaped rim 18 is arranged at the rear end of the head part 17 of the pressure piston 5, the inner wall of the ring 9 includes a groove 10, and the closed ring 9 is provided with a number (8 in the version in fig. 1-5) of relatively short slots 12 (open at the rear end of the ring 9, all for a purpose described below.

Figs 3-5 show how the bone implant 1 is operated for holding a patient's bone B at the front end part of the implant. The expansion sleeve 3 is inserted and held in a cylindrical cavity C in the patient's bone B by means of an insertion rod 21 with an externally threaded end part 23 which is screwed into the internally threaded channel 15 in the sleeve 3. The insertion rod 21, which extends along the longitudinal axis of the sleeve 3, is tubular to fit over a guide string 25. The tubular pressure piston 5, which is slidably fitted over the rod 21, is advanced along the rod 21 towards the sleeve 3 (ie from left to higher according to Fig. 3) with the largely cylindrical head part 17 at the front. After the head part 17 of the pressure piston 5 is first brought into contact with the elongated strip parts 11

at the entrance to zone r2 (see fig. 4), the 8 strip parts 11, due to the continued advance of the pressure piston 5

through the interior of the sleeve 3, expand radially outwards towards the side wall in the cavity C, thereby holding the patient's bone B securely. When the pressure piston 5 has been fully advanced in the expansion sleeve 3 (see fig. 5), the raised edge 18 will fit into the groove 10, whereby the sleeve 3 and the pressure piston 5 are locked against unwanted loosening in the axial direction, after the introduction of the implant 1. P.g.a. the (peripherally) evenly distributed slots 12 give the ring 9 a slight degree of elasticity, so that the rib 18 can be inserted into the groove 10. When the pressure piston is fully advanced in the sleeve 3, the cylindrical sleeve wall has also acquired a largely barrel-shaped contour as a result of which the opposite ends of each strip part 11 are fixed

to the vault 7 and the ring 9, respectively. As the expansion sleeve 3 is made of an elastic material, the strip parts 11 can expand radially outwards by elastic deformation, when the pressure piston 5 is advanced completely into the expansion sleeve 3. If desired, an extrudable bone cement or a bone filling material can be introduced into the sleeve 3, to be extruded through the openings 13 of the sleeve-bone boundary plate when the pressure piston 5 is advanced in the sleeve 3.

An introduction instrument 27 according to the invention, for use when implanting the bone implant 1, is shown in fig. 1 shown joined with the sleeve 3 and the pressure piston 5. The insertion instrument 27 comprises the elongated, axially knurled insertion rod 21 (on which the pressure piston 5 can be moved slidingly) with an externally threaded end portion 23 which can be screwed into the threaded opening 15 in the vault 7 of the sleeve 3 and an external smooth part 29 which starts from a threaded part 23, a hollow sleeve 31 which can be moved slidingly on the smooth part 29,

a lever 3 3 and a device 35 for advancing the hollow sleeve 31 along the smooth part 29 of the rod 21, towards the externally threaded part 23 of the rod 21. The sleeve advancing device 3 5 consists of a knurled knob 37 which is screwed onto a externally threaded part 39 of the elongated rod 21. By turning, the knob 37 will be pushed towards the sleeve 31. A nylon piece (not shown) is preferably fitted between the knob 37 and the sleeve 31. A guide pin 41 on the inner wall of the sleeve 31 is received in a longitudinal groove in the threaded part 39 (see fig. 18A). During use, the surgeon will hold the lever 33 in one hand and turn the knob 37 with the other hand, to advance the hollow sleeve 31 towards the expansion sleeve 3. The hollow sleeve 31 is brought into contact with the pressure piston 5 which is likewise mounted on the insertion rod 21, whereby the pressure piston 5 is pushed along the rod until it is advanced into the expansion sleeve 3. The cylindrical head part 17 of the pressure piston 5 is pressed, by means of the knob 37 and the hollow sleeve 31, against the elongated strip parts 11 in the expansion sleeve 3 and thereby forces these to expand, can the surgeon interrupt the advancement of the pressure piston in the expansion sleeve (to rest, assess the surgical case, or for other reasons) without relieving the force exerted against

the pressure piston of the insertion instrument 27. In such a situation, the sleeve feeding device 35, due to its construction, effectively prevent movement of the hollow sleeve 31 and the pressure piston 5 along the insertion rod 21 and away from the expansion sleeve 3.

After the implantation of the expansion sleeve 3 and the pressure piston 5 is complete, and the pressure piston is fully inserted into the sleeve, the guide string 25 and the introducer rod 21 are removed from the patient's bone, although it is taken into account that an appropriately sized introducer rod and/or guide string can be left in position in the patient's bone, thereby forming part of the implanted elongated bone implant.

A fast, bent side plate 43 which can be part of a module implant system or equipment according to the invention is shown in fig. 6 and 7. The fast, bent side plate 43 includes an elongated plate portion 45 which is arranged to be attached to the outer cortical wall of the femoral shaft, and an integrating hollow sleeve 47 which emanates from one end of the plate portion 45. The elongated plate portion 45 has an upper side 49 and an underside 51 which during use should rest against the patient's bone, while the hollow sleeve 47 is provided with a continuous, cylindrical and longitudinal channel 53 which extends from the upper side 49 to the free end of the hollow sleeve 47. As shown in fig. 7, the elongated plate part 45 and the hollow sleeve 47 form an oblique angle of approx. 130-150° to each other, and the hollow sleeve 47 can thereby extend into the intertrochanteric zone of the femur, when the elongated plate part 45 is attached to the outer cortical wall of the adjacent femoral shaft.

The phrase "adapted to be attached to the outer cortical wall" of a bone (eg a femur) is used in the description to indicate that an implant is adapted to be attached to a bone in such a way that it abuts the bone's outer cortical wall. An implant can, for example, be provided in its longitudinal direction with a number of openings for the reception of bone anchoring parts (e.g. bone screws, rivets, studs, bolts, rivets, etc.) which are used to attach the implant to the outer cortical wall.

As can be seen from fig. 6 and 7, it is in the fast,

bent side plates 4 3 elongated plate part 45 arranged three circular, through openings 55, 57 and 59 for receiving three leg screws, one of which in each opening. These three openings are offset in relation to the longitudinal axis of the plate section 45 (see Fig. 6), in order to reduce the stress concentrations in the anchored plate section and in the bone. As shown in fig. 7, the upper wall portions of the openings 55, 57 and 59 at the upper side 49 preferably consist of identical, upwardly concave and spherical surfaces. These identical, spherical surfaces are adapted for engagement with cortical and cancellous bone screws with spherical heads, as explained below. Two of these openings 57 and 59 are in connection with an elongated cavity 63 which is located at the underside 51 of the plate part 45 and which extends in the longitudinal direction from the free end 65 of the plate part 45 to a stop 67. The cavity 63 is arranged for recording, by sliding fit, of an end part of an elongated leg plate according to the invention, as described in the following. The underside 51 of the elongated plate portion 45 is slightly curved (seen in cross-section of the plate portion 45, as shown in Fig. 8) corresponding to the shape of the outer cortical wall of a femur.

Fig. 9 and 10 show an elongated bone plate 69 according to the invention, which is arranged to be attached to a patient's bone. The leg plate 69 has an upper side 71, a lower side 73 which during use should rest against the patient's knuckle, and two side surfaces 75 and 77 which connect the upper side 71 and the lower side 73 to each other. The leg plate 69 shown is equipped with 6 identical, continuous long holes, for example 79, 80 and 85, for the reception of bone screws used to fasten the plate to a patient's bone, e.g. to the outer cortical wall of the femoral shaft. In the leg plate according to the invention, there may, if desired, be arranged through openings in a number other than 6 (odd or even). The long holes are preferably alternately offset in relation to the longitudinal axis of the bone plate (see fig. 9), in order to reduce the stress concentrations in the anchored bone plate and in the bone, and the distance between the two middle holes (the third and fourth holes in fig. 9) is greater than the distance between the other pairs of mutually adjacent holes. As is clear from fig. 10, the upper side 71 has a greater width than the lower side 73, the side surfaces 75 and 77 lean inwards towards each other in the direction from the upper side 71 to the lower side 73 (i.e. downwards and inwards according to Fig. 10), and the leg plate 69 has a largely constant thickness T

from side surface 75 to side surface 77. In the embodiment according to fig. 9 and 10, the leg plate 69 comprises two parallel rails 81 and 83 which are arranged at each edge of the underside 73 and which extend largely along the full length of the plate 69. During use, only the rails 81 and 83 will rest against the outside of the patient's knuckle , to affect the bone or the periosteal vascularity as little as possible.

An important feature of the leg plate 69 is that its cross-sectional dimensions correspond to the cross-sectional dimensions of the cavity 63 in the elongated plate portion 45 of the fast, bent side plate 43. Each end of the leg plate 69 can therefore be introduced into the cavity 63, but due to the inclined side surfaces of the leg plate and the cavity, the leg plate 69 can only be introduced and removed from the cavity 63 by mutual axial movement through the opening of the cavity 63 at the free end 65 of the plate part 45. Separation or joining by relative movement in the vertical direction is not possible, and the leg plate 69 cannot be turned in relation to the fast, bent side plate 43 after being introduced into the cavity 63 (see fig.17 which shows the "dovetail" engagement between the plate part 45 and the leg plate 69). When one end of the leg plate 69 is inserted into the cavity 63 and rests against the stop 67, the openings 57 and 59 in the bent side plate 43 will be flush with the underlying openings, respectively. 79 and 85

in the leg plate 69. By using two bone screws which are inserted through the two pairs of overlapping openings, and screwed into the patient's bone, the leg plate 69 can be fixed, in axial alignment, to the elongated plate part 45 of the side plate 43 in a stable and secure connection which will provide an effective increase in the life of the plate part 45 in the living organism.

In a preferred modular system according to the invention, three leg plates of different lengths and of the type shown in fig. 9, with respectively four, six and eight long holes, for use either separately or as an extension of the side plates.

The elongated leg plate 69 can also be used on its own as a conventional leg plate, e.g. in the treatment of diaphyseal-femoral fractures. The six holes in the plate are elongated and can therefore each accommodate one or two screws during use.

The upper parts 107 of the identical holes at the upper side 71 are concave upwards and spherically rounded around the entire opening. These identical, spherically rounded surfaces are adapted for engagement with cortical and cancellous bone screws with spherical heads, as described below.

The leg plate 69 is preferably slightly curved, (seen in cross-section in Fig. 10) corresponding to the shape of the human femur shaft. Seen in cross-section, the upper side 71 and the lower side 73 form two concentric circular arcs with a center 0, while the side surfaces 75 and 77 form two straight lines which, by being extended, extend through the center 0 and define an intermediate angle A.

Two self-tapping cortical bone screws 89 and 91 that can be included

in a modular implant system according to the invention, is shown in fig. 11A and 11B. The screws 89 and 91 have identical heads 93 and identical shafts 97 and 99 which are externally threaded along practically the entire length of the shaft, the only difference being that the shaft 97 of the screw 89 is longer than the shaft 99 of the screw 91. Two self-tapping cancellous bone screws 101 and 103 which can form part of a modular implant system according to the invention, is shown in fig. 12A and 12B. The heads 93 and screws 101 and 103 are identical to the heads of the cortical screws 89 and 91, while the shafts of the cancellous bone screws 101 and 103 which are only externally threaded at the free shaft end are identical, except that the shaft of the screw 101 includes a longer, unthreaded portion than the shaft of the screw 103. Another pair of self-tapping cortical screws 90 and 92 is shown in fig. 32 and 32A. These screws are identical to screws 89 and 91, except that a shaft portion of screws 90 and 92 is not threaded. As shown in fig. 13, in each of the identical heads of the screws 89, 91, 90, 92, 101 and 103 an identical, axially extending recess 95 with parallel, axially extending side walls is arranged, for receiving a screw driver instrument (e.g. a screwdriver ). The recess has a generally star-shaped cross-section, for example the generally star-shaped Torx (trademark) drive cross-section shown in fig. 13, or the generally star-shaped cross-section of a Pozidriv (trademark)-

traces. If desired, the diameter of the cortical and/or cancellous bone screws can decrease in one or more steps or decrease evenly towards the free shaft end, in order to increase the gripping force against the adjacent femoral cortex.

Another, important feature of the design of the screw head 93 is that the underside 105 of the head 93 is spherically rounded largely in correspondence with the spherically rounded, upper side wall portions of the screw-recorder openings in the bent side plate 43 and in the elongated leg plate 69. Fig. 14 shows the permitted angular rotation from side to side of one of the four screws according to fig. 11A, 11B, 12A and 12B (shown in broken lines) in one of the screw-receiver openings (opening 80) in the leg plate 69. As a result of the generally corresponding, spherically rounded head undersides 105 and the upper wall portion 107 of the opening 80, the screw 89 can turn through an angle of approx. 3 0° in a plane perpendicular to the longitudinal axis of the leg plate 69. A practically unlimited angular rotation can take place in a plane parallel to the longitudinal axis of the leg plate. But when the leg screw 89 is placed at the very end of the opening 80, an unlimited angular rotation can only take place in a direction in a plane parallel to the longitudinal axis of the leg plate, while only a rotation of approx. 15° in relation to the vertical line is possible in the opposite direction in the same plane. The radius of the spherically rounded upper side wall portion 61 of the openings 55, 57 and 59 in the bent side plate 43 is equal to the radius of the upper side wall portion 107 of the openings 80 in the leg plate 69, as shown in cross section in fig. 14. The screws 89, 91, 101 and 103 can therefore be turned generally in relation to the elongated plate part 45 within a cone surface with an apex angle of approx. 30°, when they are fully inserted into one of the openings 55, 57 and 59. (When the bent side plate is connected to an elongated leg surface, however, this freedom of rotation is considerably limited for two screws inserted through both plates.) The ability of the leg screws to be turned in various angular positions in an elongated leg plate or bent side plate, Increases the possibilities of adaptation in fixation of oblique fractures and "complicated fracture patterns, eg, butterfly fractures. Angular rotation allows the bone screws to be placed approximately perpendicular to many fracture lines, serving to increase the number of bone fragments that can be retained directly by at least one screw.

The elongated epiphyseal/metaphyseal implant 1, the fast bent side plate 43, the elongated bone plate 70 with four long holes and a number of cortical bone screws 89 can be joined and secured to a patient's upper femur F in a manner as shown in FIG. 15 - 17 to form a side plate hip bone assembly, where the effective length of the bent side plate elongated plate portion is extended at the elongated leg plate. The implant 1 is first inserted into a cavity that has been prepared in a hurry

the femur and which must be expanded at its open end to accommodate it

side plate 43 of the hollow sleeve 47 which is then pushed into the cavity so that a part of the cylindrical stem part 19 of the pressure piston 5 is taken up by sliding fit in the cylindrical channel 53 in the sleeve 47, and one end of the leg plate 70 is pushed into the cavity 63 in the side plate 43 until it rests against stop 67, after which the entire assembly is anchored to the femur F with a number of cortical bone screws 89 which are inserted through holes in the side plate 43 and the leg plate 70. If desired, one or more conventional fixing studs can

(for example Knowles pins) which are not connected to the implant 1 and the bent side plate 43, are also implanted and are thereby oriented largely parallel to the direction of the implant 1 shown in fig. 16. The leg plate 70 can of course be omitted from the assembly according to fig. 16, if the plate part 45 has a length which is sufficient without extension in a special, surgical case.

A femoral medullary inner rod 109 which can form part of a modular implant system or equipment according to the invention is shown in side views at right angles to each other in fig. 19 and 20. The rod 109 has a quick end 111 and a far end 113 and a pair of transverse through channels 115, for receiving the leg screw 90, at the far end 113. One or two through channels 116 for receiving anchoring leg screws, can also be arranged at the fast end 111. The rod 109 has a far end part 117 and a rectilinear, fast end part 119. As can be seen from fig. 19, the rod 109 is slightly curved, in order to be able to lie at the front and back flush with the femur after implantation, and such a curvature is not shown in fig. 20, as the rod 109 must run in a straight line in the lateral-medial plane after implantation. Rod 109 is shown in cross-section in fig. 21. The cross-section has a closed profile and an outer periphery comprising a number (e.g. 6) of evenly rounded tips, (e.g. 121) all terminating on the same, first circle and which are connected to each other through an equal number of evenly rounded depressions (for example 123) which all have their deepest point lying on the same, second circle which is concentric with the first circle and of smaller diameter than this. These alternately arranged tips and recesses will greatly increase the stability against axial rotation in relation to the patient's bone of the implanted rod 109, while the evenly rounded design will result in a significant reduction in the possibilities of damage to the bone tissue in the marrow hole wall. Furthermore, the bar's alternately raised and recessed outer contour, as shown in fig. 21, entail extensive re-vascularization of the bone tissue of the medullary canal wall after broaching. Fig. 21 further shows that the rod 109 is axially tubular with an axial channel 125 which extends from the distal tip 127 of the hollow rod 109 to the sharp tip 129 of the rod. A diametrical slot 120 is arranged in the sharp tip 129, to connect with suitable insertion and extraction tools.

Fig. 23 - 24 show an elongated connecting piece 139,

a locking screw 141 and a locking tab 142 for securing an epiphyseal/metaphyseal implant 1 to the medullary inner rod 109 at the sharp end 111 of the rod 109, to create a Y-nail type assembly. The connecting piece 139 includes at one end an elongated, cylindrical cavity 143 which runs flush with the longitudinal axis of the connecting piece 139 and is designed for receiving, by sliding fit, the free end of the stem part 19 of the implant's 1 pressure piston 5. The connecting piece 139 further includes a cylindrical, through channel 145 which

S

proceeds at an oblique angle of approx.;13 5° ice relation to the aforementioned

~X

longitudinal axis, and an elongated, partially recessed and partially internally threaded channel 147 which runs flush with said longitudinal axis at the end of the elongated connecting piece 139 furthest from the cavity 143. The channel 147 is arranged for receiving the locking screw 141 and the locking tray 142, and both channel% 147 and

the cavity 143 opens into a through channel 145. The diameter of the through channel 145 is slightly larger than the maximum cross-sectional dimension of the quick end part 119 of the marrow hole inner rod 109, so that this part can be accommodated, with a tight sliding fit, in the through channel 145, with the possibility for rotational and translational adjustment of the connection piece 139 in relation to the core hole inner rod 109. The connection piece 139 and the core hole inner rod 109 can be securely locked against mutual translational and rotational movement by screwing forward the locking screw 141 in the partially threaded channel 147 behind the locking tray 142 , until the front side 144 of the locking tray 142 is forced very firmly against the outer surface of the fast end part 119, and can then be released again, if desired simply by unscrewing the screw 141. The front side 144 of the locking tray 142 has a grooved contour that can be fitted tightly and in engagement with the rod's 109 knurled outer contour and thereby favor the secure interlocking of the rod n 109 and the connecting piece 139. The locking screw 141 and the locking shoe 142 are joined during use, for example by means of an embedded wire or mike connection, before the locking tray 142 is to be retracted by unscrewing the screw 141 while the two elements can at the same time be turned independently in relation to each other while screwing in and unscrewing the screw 141.

In the alternative version according to fig. 22, a hollow sleeve 131 with a smooth, cylindrical outer surface is removably attached to the outside of the quick end portion 119 of the marrow hole inner rod 109 (having a knurled cross-sectional shape as shown in Fig. 21) by means of a locking screw 135 with a head and an externally threaded shaft which is introduced through a central opening in the upper end wall of the sleeve 131 and screwed into a central, internally threaded sleeve 137 in the upper end of the rod 109. There is an advantage to the embodiment according to fig. 22 that the diameter of the rod's 109 rectilinear, fast end is effectively increased and exceeds the maximum cross-sectional dimension of the cross-section according to fig. 21. The hollow sleeve 131 should extend beyond at least to the point which absorbs the maximum transmitted bending moment during normal use, and which is usually located in the trochanteric zone of the femur, but not all the way along the rod 109 to the midpoint between the distal and distal tips of the rod 127 and 129. When using the hollow sleeve 131, the contour of the front face of the locking tray 142 must be suitably adapted, or the locking tray can be omitted so that only the locking screw is used.

The marrow hole inner rod 109, the connecting piece 139, the locking screw 141, the locking tray 142 and a bone implant 1 can be joined as shown in fig. 25, for the creation of a Y-nail type assembly in a femur F, whereby the implant 1 and the piece 139 together form the elongated cross-piece of the Y-nail. The epiphyseal/metaphyseal implant 1 was first inserted into a cavity ' which has been prepared in the femur and which must be expanded towards the open end to receive the connecting piece 139. The piece 139 is then advanced into the prepared bone cavity and oriented so that a part of the pressure piston's 5 trunk part 19 is accommodated by press fitting in the cavity 143, and that the through channel 145 is brought approximately flush with the femur's marginal channel. The rod 109 is advanced forward through an opening created by conventional means in the distal femur wall and through the continuous channel 145 in the piece 139, until the far end part 117 of the rod 109 is located in the far femur and the distal end part 119 of the rod 109 is located in the continuous channel 145. By careful adjustment, the rod 109 is then brought into the desired position in relation to the femur F and the connecting piece 139, after which the connecting piece 139 is anchored to the marrow hole inner rod 109 using the locking screw 141 and the locking tray 142. If desired, a cortical bone screw 90 of the type shown in fig. 32A, with a large shaft length, is introduced in a conventional manner through one or both of the transverse channels 115, for locking the rod 109 to the far femur. The set screw 135 can also be screwed into the channel 137, even if the sleeve 131 is not used, to prevent ingrowth of bone tissue into the threads in the channel 137.

It is contemplated that a connecting piece similar to piece 139 may, if desired, be used for joining an epiphyseal/metaphyseal implant, of the type implant 1, to the far end portion 117 of the medullary inner rod 109, with the epiphyseal/metaphyseal the metaphyseal implant placed in the far condylar zone of the femur, largely perpendicular to the portion 117. In such a case, the through channel in the connecting piece, corresponding to the through channel 145 in the piece 139, will run largely perpendicular to the longitudinal axis of the connecting piece.

An outer, bent side plate 149 which can form part of a modular implant system or equipment according to the invention is shown in fig. 26 and 27. This side plate 149 includes an elongated plate portion 151 which is designed to be attached to the outer cortical wall of the far femur shaft, and an integrating, hollow sleeve 153 which emanates from one end of the plate portion 151. As can be seen from fig. 27, the plate portion 151 is slightly bent near the line R in adaptation to the anatomical curvature of the lateral far femur. The elongated plate part 151 has an upper side 155 and a lower side 157 which during use should rest against the patient's bone, and the hollow sleeve 153 is equipped with a longitudinal, cylindrical and continuous channel 159 which extends from the upper side 155 to the free end of the hollow sleeve 153. As shown in fig. 27, the elongate plate part 151 and the hollow sleeve 153 are arranged largely at right angles, so that the sleeve 153 can extend into the far condyle zone of the femur, when the elongate plate part 151 is attached to the adjacent outer cortical wall of the far femur shaft. The continuous channel 159 is dimensioned for receiving, by sliding fit, a part of the stem part 19 of the pressure piston 5 at an elongated epiphyseal/metaphyseal implant 1. The underside 157 has a slightly curved cross-sectional shape, similar to the cross-section in fig. 8, (for the quick side plate 43) equivalent to a far femur's outer cortical wall.

Three circular, through holes 161, 163 and 165 are arranged in the plate part 151, for receiving three bone screws (for example cortical screw 89), one of which in each hole. These three holes are offset in relation to the longitudinal axis of the plate part 151 (see fig. 26), in order to reduce the stress concentrations in the anchored plate part and in the bone. Holes 161, 163 and 165 are identical to, respectively. the holes 55, 57 and 59 in the fast, bent side plate 43. The far, bent side plate 149 is likewise equipped with an elongated cavity 167 which is arranged in the underside 157 of the plate part 151. The cavity 167 is identical to the cavity 63 in the fast, bent side plate 43. The cavity 167 can therefore accommodate one end of the elongate leg plate 69 in a sliding "dovetail" engagement connection (see Fig. 17), and when the end of the leg plate abuts the abutment 169, the holes 163 and 165 will be flush with the two underlying end openings, for example the openings or 79 and 85, in leg plate 69.

The distal bent side plate 149, an elongated epiphyseal/metaphyseal implant 1 and a number of cortical bone screws 89 can be joined and secured to a patient's femur F as shown in fig. 28, thereby forming a far side plate pin assembly, where the effective length of the side plate's elongated plate portion is extended by the elongated leg plate. The preferred surgical process is analogous to that previously described in connection with the assembly according to fig. 15 - 16. The leg plate 69 can of course be omitted from the assembly according to fig.

28, if the length of the plate portion 151 is sufficient without extension, in a special, surgical case.

A far support plate 171 according to the invention is arranged to be fixed to the outer cortical wall of the lateral far femur, as shown in fig. 29 and 30. The support plate 171 includes a relatively flat and elongated sharp part 173 for attachment to the lateral far femur shaft and a three-dimensionally profiled far part 175 which should correspond to the average shape of the lateral femoral condyle in adults. The distal portion 175 includes a generally rounded head 177 at the distal end of the plate 171, a generally widened main portion 179 having a greater maximum width than the head 177 and the quick portion 173, and a neck portion 181 having a minimum width W that is substantially less than the maximum widths of the head 177 and the main part 179. As shown in cross-section, the underside of the far support plate 171 is profiled in its length corresponding to the outer cortical wall of the far femur.

The far support plate 171 is designed to be fixed to the outer cortical wall of the lateral far femur by means of bone screws which are received in cavities in the plate. In the fast batch 173

three circular and through holes 183, 185 and 187 are therefore arranged for the reception of three bone screws, (e.g. cortical screw 89), one of which in each hole. These three holes are offset in relation to the longitudinal axis of the fast part 173

(see fig. 29) and are identical to respectively the holes 55, 57 and 59 in the bent side plate 43. Furthermore, there is an elongated hole 189 in the head 177 and two elongated holes 191 and 193 in the main part 179, one of which on each side of the main part 179. Each of the holes 189, 191 and 193 is substantially identical to the holes in the elongate leg plate 69, and each hole is accordingly designed to receive two leg screws (or only one if desired) with a head 93, and to allow the general angular rotation of the screws when these are fully introduced through the opening.

Furthermore, it is often very desirable to be able to use a distal support plate in connection with a pair of fracture-reducing French screws that extend through the distal condylar zone of the femur. Such French screws are completely screwed into the bone before the implantation of the far support plate and consequently cannot practically be introduced through the plate. It is an important feature of the far support plate 171 that the far part 175 of the plate is designed in such a way that on the outside of the plate periphery there remains space towards the neck 181, which provides space for two fracture-reducing French screws that extend through the far condylar zone of the femur, on both sides of the neck 181. These two French screws are in fig. 29 shown in broken lines as elements 195 and 197.

The far support plate 171 is also provided with an elongated cavity 199 which is arranged in the underside of the hot part 173. The cavity 199 is identical to and arranged to create the same leg plate "dovetail" engagement connection as the cavity 63 in the bent side plate 43 and the cavity 167 in the bent side plate 149. When the end of the leg plate 69 is inserted into the cavity 199 to abut against a stop 201 in the cavity, the holes 185 and 187 will be flush with the two underlying end openings, for example the openings and 79 and 85, in leg plate 69.

The far support plate 171, the elongated leg plate 69,

a number of cortical bone screws, such as screw 89, and a number of cancellous bone screws, such as screw 101, may be joined and anchored to a patient's femur F in a manner as shown in FIG. 31. Two French screws (not shown in Fig. 31) are first inserted completely into the distal condylar zone, if desired, to reduce a fracture in said zone. These implanted French screws

are placed so that they are generally located in the lateral-medial plane, and with such a mutual distance that they are located close to the two opposite sides of the neck 181 of the part 175 (see fig. 29). The distal support plate 171 is then secured to the lateral femur, with the neck 181 fitted between the two previously implanted and fracture-reducing French screws, using the bone screws 101 inserted through holes 189, 191 and 193 (one or two screws can be inserted through each of the holes 189, 191 and 193), and a leg screw 89 is introduced through the opening 183. The leg plate 69 is then pushed into the cavity 199 until the end of the plate rests against the stop 201, and the leg screws 89 are screwed to the femur F through the holes 185 and 187. Finally, the leg screws 89 are firmly screwed to the femur F through some or all of the four remaining holes in the leg plate 69, outside the cavity 199. The far support plate 177 can of course be implanted without the leg plate 69, if the length of the fast part 173 is sufficient without extension, in a especially, surgical case.

Claims (4)

1. Set for use in the treatment of femur disorders of various types resulting from injury, disease or congenital defect, comprising the following components: an elongated epiphyseal/metaphyseal implant (1), with an anterior end portion and a posterior end portion, for holding the bone at the front end part, a medullary inner rod (109) with a distal end (113) and a proximal end (111), a bent side plate (149) consisting of an elongated plate part (151), for attachment to the outer cortical wall of the femoral shaft, and an integrating hollow sleeve (153) extending at an angle from one end of the plate portion (151) to extend into the femur, when the plate portion (151) is secured to the cortical wall, and means (139, 141, 142, 147) for joining the epiphyseal/metaphyseal implant (1) and the medullary inner rod (109) at one of the ends (111, 113) of the rod (109) so that the epiphyseal/metaphyseal implant (1) forms an angle with the medullary inner rod ( 109).characterized in that the set's component is dimensioned in such a way that the elongated epiphyseal/metaphyseal implant (1) can be connected to the bent side plate (149) by inserting the rear end part of the implant (1) into the hollow sleeve (153), and where the elongated epiphyseal/metaphyseal implant (1) can also be connected to the medullary inner rod (109) by using said connecting means (139, 141, 142, 147). 2. Set according to claim 1, characterized in that it comprises an elongated leg plate (69) for attachment to the outer cortical wall of the femoral shaft, the bent side plate (149) and the elongated leg plate (69) being dimensioned in such a way that the elongated leg plate (69) can be connected in axial alignment with the bent side plate (149) plate part (151) at the opposite end in relation to the hollow sleeve (153), thereby forming an extension of the plate part (151)'s effective length. 3. Set according to claim 2, characterized in that it further comprises a distal support plate (171) which is arranged to be attached to the outer cortical wall of the lateral distal femur and which includes a relatively flat and elongated, proximal part (173) for attachment to the lateral distal femur shaft, where a relatively arc-shaped, distal part (175) for attachment to the lateral distal femoral condyle, where the distal support plate (171) and the elongate bone plate (69) are dimensioned such that the elongate bone plate (69) is dimensioned such that the elongate bone plate (69) can be connected in axial alignment with the distal support plate's (171) elongated proximal part (173) at the opposite end in relation to the relatively arcuate distal part (175) and thereby form an extension of the proximal part's (173) effective length. 4. Set according to claim 1, characterized in that the connecting means comprise an elongated connecting piece (139) with a longitudinal axis and an elongated cavity (14 3 ) which runs flush with the longitudinal axis and which opens towards one end of the connecting piece (139) and is adapted for receiving the rear end portion of the epiphyseal/metaphyseal implant (1), and a through channel (145) which forms an angle with the longitudinal axis and is adapted to receive one end of the medullary inner rod (109) so that the connecting piece (139) can be moved along the rod (109) and rotated about the axis of the rod (109), and locking means (141, 142, 147) for releasably locking the connecting piece (139) to the marrow hole inner rod (109) and thereby preventing mutual translational and rotational movement of the connecting piece (139) ) and the rod (109) .